1. Field of the Invention
The invention relates to a semiconductor device having a semiconductor element mounted on an insulating base, such as an optical device like a solid-state imaging device using an imaging element such as a CCD (Charge Coupled Device) and a CMOS (Complementary Metal-Oxide Semiconductor), and a manufacturing method of the semiconductor device.
2. Related Art
With reduction in size of electronic equipments such as portable terminals, reduction in size of semiconductor devices has been demanded in recent years. In addition to reduction in size and thickness of semiconductor devices, quality of a reference surface is also important for secondary mounting of a semiconductor device onto a set to which the semiconductor device is to be mounted. Improvement in quality of a mounting surface has therefore also been demanded. Among semiconductor devices, this market demand is strong especially for optical devices such as solid-state imaging devices that have been widely used in video cameras and still cameras.
FIGS. 5A and 5B show a structure of a conventional solid-stage imaging device. FIG. 5A is a plan view of the solid-state imaging device. FIG. 5B is a cross-sectional view taken along line Vb-Vb′ in FIG. 5A.
The solid-state imaging device is formed by using an insulating base 1. A frame 2 is provided on the periphery of the insulating base 1, and a surface of the insulating base 1 in a region located inside the frame 2 serves as an element mounting surface 3. A plurality of wiring portions 4 are extended from the periphery of the element mounting surface 3 to a bottom surface of the insulating base 1, and an optical function element 6 is fixed to the element mounting surface 3 by an adhesive 5. The optical function element 6 and the wiring portions 4 are electrically connected to each other by thin metallic wires 7. A light-transmitting protector 9 is bonded on the optical function element 6 by an adhesive 8, and a region between the frame 2 and the optical function element 6 is filled with a sealing resin 10 so as to bury the thin metallic wires 7. A top surface of the frame 2 is a mounting reference surface 13. Note that FIG. 5A is shown in a state of seeing through the sealing resin 10.
In such a solid-state imaging device, a process of dropping a liquid sealing resin by a dropping nozzle has been commonly used to fill the region between the frame 2 and the protector 9 and the optical function element 6 with the sealing resin 10. A purpose of filling the region with the sealing resin 10 is to prevent malfunction of the optical device and degradation of capability and functions of the optical device from occurring due to, for example, incidence of stray light onto a light-receiving surface of the optical function element 6. In order to accomplish this purpose, it is necessary to fill the sealing resin 10 up to an upper end face of the light-transmitting protector 9 bonded on the optical function element 6 by the adhesive 8.
Japanese Laid-Open Patent Publication No. 2006-186288 proposes a method of filling a liquid sealing resin by dropping, and bringing a package forming member into contact with a frame and the liquid sealing resin.